package com.icinfo.cloud.provider.common.utils;

import com.icinfo.cloud.provider.common.exception.BusinessException;
import org.apache.commons.codec.binary.Base64;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.StringUtils;
import sun.misc.BASE64Decoder;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;
import java.math.BigInteger;


/**
 * Created by hspcadmin on 2018/10/25.
 */
public class AesUtil {
    private static Logger logger = LoggerFactory.getLogger(AesUtil.class);
    //算法
    private static final String ALGORITHMSTR = "AES/ECB/PKCS5Padding";

    /**
     * 将byte[]转为各种进制的字符串
     *
     * @param bytes byte[]
     * @param radix 可以转换进制的范围，从Character.MIN_RADIX到Character.MAX_RADIX，超出范围后变为10进制
     * @return 转换后的字符串
     */
    public static String binary(byte[] bytes, int radix) {
        return new BigInteger(1, bytes).toString(radix);// 这里的1代表正数
    }

    /**
     * base 64 encode
     *
     * @param bytes 待编码的byte[]
     * @return 编码后的base 64 code
     */
    public static String base64Encode(byte[] bytes) {
        return Base64.encodeBase64String(bytes);
    }

    /**
     * base 64 decode
     *
     * @param base64Code 待解码的base 64 code
     * @return 解码后的byte[]
     * @throws Exception
     */
    public static byte[] base64Decode(String base64Code) throws Exception {
        return StringUtils.isEmpty(base64Code) ? null : new BASE64Decoder().decodeBuffer(base64Code);
    }


    /**
     * AES加密
     *
     * @param content    待加密的内容
     * @param encryptKey 加密密钥
     * @return 加密后的byte[]
     * @throws Exception
     */
    public static byte[] aesEncryptToBytes(String content, String encryptKey) throws BusinessException {
        try {
            if (encryptKey != null && encryptKey.length() > 16) {
                encryptKey = encryptKey.substring(0, 16);
            }
            KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
            keyGenerator.init(128);
            Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
            cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(encryptKey.getBytes(), "AES"));

            return cipher.doFinal(content.getBytes("utf-8"));

        } catch (Exception e) {
            e.printStackTrace();
            throw new BusinessException("AES aesEncryptToBytes error");
        }
    }


    /**
     * AES加密为base 64 code
     *
     * @param content    待加密的内容
     * @param encryptKey 加密密钥
     * @return 加密后的base 64 code
     * @throws Exception
     */
    public static String aesEncrypt(String content, String encryptKey) throws BusinessException {
        logger.debug("加密秘钥：" + encryptKey);
        logger.debug("加密明文：" + content);
        if (encryptKey != null && encryptKey.length() > 16) {
            encryptKey = encryptKey.substring(0, 16);
        }
        //content = base64Encode(content.getBytes("UTF-8"));
        //content = Hex.encodeHexString(content.getBytes("UTF-8"));
        content = base64Encode(aesEncryptToBytes(content, encryptKey));
        logger.debug("加密密文：" + content);
        return content;
    }

    /**
     * AES解密
     *
     * @param encryptBytes 待解密的byte[]
     * @param decryptKey   解密密钥
     * @return 解密后的String
     * @throws Exception
     */
    public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws Exception {

        byte[] decryptBytes = aesDecryptByBytesByte(encryptBytes, decryptKey);
        return new String(decryptBytes);
    }

    public static byte[] aesDecryptByBytesByte(byte[] encryptBytes, String decryptKey) throws Exception {
        if (decryptKey != null && decryptKey.length() > 16) {
            decryptKey = decryptKey.substring(0, 16);
        }
        KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
        keyGenerator.init(128);

        Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
        cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(decryptKey.getBytes(), "AES"));
        byte[] decryptBytes = cipher.doFinal(encryptBytes);
        return decryptBytes;
    }

    /**
     * 将base 64 code AES解密
     *
     * @param encryptStr 待解密的base 64 code
     * @param decryptKey 解密密钥
     * @return 解密后的string
     * @throws Exception
     */
    public static String aesDecrypt(String encryptStr, String decryptKey) throws BusinessException {
        try
        {
            if (decryptKey != null && decryptKey.length() > 16) {
                decryptKey = decryptKey.substring(0, 16);
            }

            return StringUtils.isEmpty(encryptStr) ? null : aesDecryptByBytes(base64Decode(encryptStr), decryptKey);
        } catch (Exception e){
            e.printStackTrace();
            throw new BusinessException("aesDecrypt error");
        }

    }

    public static byte[] aesDecryptByte(String encryptStr, String decryptKey) throws Exception {
        if (decryptKey != null && decryptKey.length() > 16) {
            decryptKey = decryptKey.substring(0, 16);
        }
        return StringUtils.isEmpty(encryptStr) ? null : aesDecryptByBytesByte(base64Decode(encryptStr), decryptKey);
    }

}
